1. Field of Invention
The present invention pertains to the field of medical probes. More particularly, the present invention is directed to a probe cover having reinforced layers for covering a medical probe prior to insertion into a sterile field.
2. Description of the Related Art
In the medical field, it is well know to use invasive probes for many various applications. Typical medical probes include, but are mot limited to, endoscopes, ultra-sound probes, rectal or vaginal probes, esophageal probes, as well as surgical instruments. Such medical probes are manipulated from either a sterile or non-sterile field, with the insertion end of the probe disposed within a sterile field. In so placing the probe, it is necessary that the portion of the probe in the sterile field be maintained as sterile. Accordingly, it is known in the art to provide a sheath or cover over the insertion end of probe prior to insertion into the sterile field. Application of the cover onto the probe is normally followed with application of an elastic gasket or a restraining band around one end of the cover to retain the cover thereon.
FIGS. 1 and 2 illustrate one device of the prior art. A sheath 10 for receipt on the end of an endoscope 40 or other medical probe is fabricated from a single layer of flexible material. Typically, the material is a medical grade plastic. The sheath 10 defines a tubular configuration defining a receiving end 12 configured to receive a distal end 42 of the endoscope 40. To this extent, an opening 14 is defined by the receiving end 12 for receiving the endoscope distal end 42. A throat 16 is defined a selected distance from the receiving end 12. The throat 16 is adapted to closely receive the endoscope distal end 42. A sleeve portion 18 is defined between the throat 16 and the distal end 20 of the sheath 10.
A typical sheath 10 is fabricated from a single thickness of flexible plastic film, which, in one tested device, provides approximately 0.35 pounds of tensile strength. While this strength is capable of preventing puncture or other destruction of the sheath 10, it is insufficient to retain the sheath 10 on the endoscope 40 without assistance. Accordingly, a retainer 28 is provided to maintain the position of the sheath 10 on the endoscope 40 once positioned. The retainer 28 is typically an elastomeric or rubber band.
As best illustrated in FIG. 2, the endoscope first end 42 is inserted into the receiving end 12 and through the throat 16. The retainer 28 is then placed over the throat 16 of the sheath 10. The sleeve portion 18 is then inverted over the endoscope 40 to reveal the distal end 42 and the inner surface of the sleeve portion 18, both of which are maintained as sterile.
While the retainer 28 serves to maintain the position of the sheath 10 on the endoscope 40, it creates a raised portion having a height depicted at 26. This raised portion 26 must be taken into account when determining where the endoscope 40 or other medical instrument is to be inserted into the patient. The raised portion 26 can require a larger surgical opening in certain situations, or can create additional discomfort to a patient during insertion and removal into a patient's natural body opening. The retainer 28 also has a tendency to move along the length of the endoscope 40 due to the interference between the raised portion 26 and the patient. It is also known that the application of such a retainer 28 can be difficult due to the required tensile strength and the small size thereof. The retainer 28 is, in certain situations, difficult to place while maintaining a sterile field including the distal end 42 of the endoscope 40 and the interior surface of the sleeve portion 18 of the sheath 10.
Prior art devices have normally involved the mounting of a fully extended sheath onto a carrier. In order to extend the probe into the entire length of the sheath, the medical technician or doctor will insert the probe through the sheath opening and slowly manipulate the tip of the probe such that it travels through the sheath length to its nose. This process can result in inadvertent contact with the wall of the sheath which will engage or become in direct contact with the patient.
Other devices have been developed to overcome these and similar problems associated with the manufacture and application of medical probe sheaths. Typical of the art are those devices disclosed in the following U.S. Patents:
Pat. No.Inventor(s)Issue Date3,308,940T. Morris, Jr.Mar. 14, 19673,809,230G. W. PoncyMay 7, 19743,847,280G. W. PoncyNov. 12, 19744,062,239C. F. Fowler, et al.Dec. 13, 19774,164,285H. P. DormanAug. 14, 19794,165,000G. W. PoncyAug. 21, 19794,197,944D. G. CatlinApr. 15, 19804,241,828P. A. Bourdelle et al.Dec. 30, 19804,614,442G. W. PoncySep. 30, 19864,684,018E. JärundAug. 4, 19874,757,381D. H. Cooper et al.Jul. 12, 19884,823,949H. BalaApr. 25, 19895,069,337H. BalaDec. 3, 19915,667,068S. W. WeaverSep. 16, 19975,769,224R. Poncy et al.Jun. 23, 19985,795,632M. BuchalterAug. 18, 19986,224,543C. E. Gammons et al.May 1, 2001
Of these devices, that disclosed by Weaver ('068) is a protective cover for use in the storage of an endoscope. The protective cover is a tubular member defining a passageway running lengthwise through the member from end to end. A tapered portion is defined at one end for holding the endoscope in place as it is inserted into the passageway. A narrowed portion of the passageway is located at or near the distal end of the tubular member.
The '224 patent issued to R. Poncy et al., discloses a sterile packaging system for a pipetter sheath. The packaging system comprises two inner thermoplastic strips sandwiched between two outer paper covers. The inner strips and outer covers are connected along a tear seal formed by an electromagnetic heat sealer. The tear seal is generally in the shape of a pipetter such that the sheath is held in place by virtue of its conformity with the pipetter.
The remainder of the cited prior art disclose various embodiments of sheaths which are configured to cover the end of the probe. Specifically, the end of the sheath is closed. By having a closed end, the medical probe is retained within the sheath without risk of the sheath being pulled over the probe. While many applications are conducive to the use of a probe whose distal end is enclosed within a sheath, there are many applications where the distal end of the medical instrument or probe must be unencumbered.